Production of artificial filaments from viscose solution



M ay 23, 1933. BERNSTEIN 1,910,879

PRODUCTION OF ARTIFICIAL FILAMENTS FROM VISCOSE SOLUTION Filed July 11, 1929 M4 520 5 V f Patented May 23, 1933 ARNOLD BERNS'IEIN, or MANNHEIM, GERMANY, AssIeivon T ZELISTQFFFABRIK- WALDHOF, 0F MANNIIEIM-waLDHoF, GERMANY PRODUCTION or ARTIFICIAL FILAMENTSEROM vIscosE SOLUTION Application filed July 11, 1929, Serial No. 377,465, ai in Germany July 1a, 1928.

This invention relates to a method of and apparatus for producing artificial filaments from viscose solutions.

At the present time in the production of 5 artificial filaments and the like from viscose solution in order to obtain goods fit forcommercial use, the viscose solution is generally pressed through fine orifices into a precipitant which consists of a mixture of salts and i I ample with a bath containing a considerable excess of neutral salts. The object in using such aprecipitant is to exercise a mild action on the filament separating out in the acid liquid. Subsequently precipitation of i the Xanthogenate takes place followed immediately by a transformation into cellulose hydrate. I

Such spinning baths, however, possess the in an admixed state in one bath and that the action of the acidsparticularly when using high concentrations sets in very quickly after l I the introduction of the viscoseinto the precipitant. This results in decomposition of the viscose which strikes deep at a very early stage of the formation of the artificial filament which, amongst other things, renders a 36 narily difiicult. V

Attemps have already been made to efl'ect a separate action of salts and acids in which filaments separated out in pure salt solution are conveyed into other baths containing only acids or in which filaments withdrawn from pure salt baths are wound up onspools or the like which rotate in an acid bath. This manner of using separate baths is, how- ;ever, not satisfactory as firstly strong adher- 4 ence of the filaments to one another can easily take place, and secondly, the artificial filaments after action of a pure salt solution do not in general yet possess sufficient -strength to endure the passage necessary on 4 "being transferred to another apparatus.

acids. Good results are obtained, for ex-' disadvantage that salts and acids are present vessel wh spinning nozzles, f and f fine drawing out of the threads extraordi- One object of the invention is to provide a method of producing artificial filaments wherein coagulation and fixation of the filaments take place in separate stages without damage to the filament on being transferred from one stage to the next;

Another object of the invention is to provide apparatus for forming artificial filaments wherein the filament may be transferred without damage from one part ofthe apparatus toanother. I I p r The invention is more particularly described with reference to the accompanying drawing forming part of this specification and showing apparatus adapted for carrying out the process. On the drawing: Fig lisra view, chiefly in cross-section, of

apparatus in accordance with thein-vention;

andv a. p d

Fig. 2 is atop "iew of the apparatus shown The apparatus comprises I precipitant in i ch is sub-divided by the wall 9 into two, chambers A and B. (1; denotes the p the inlet pipes for the salt solution and acid respectively, 9 and g/[overflow conduits for the withdrawal of the saltsolution and acidrespectively out of the precipitant container. Filament guides hare provided over which the filaments I) pass to the spooling devices (Z. I r

The spinning process may be carried out with thisappartus', for example in the following manner, At the end where the vis cose solution enters a pure saltsolution havmg for, example, a 30% salt content is introduced into the vessel through pipe f and is withdrawn again through the overflow device ,9 located somewhat centrally of the bath. The secondpart B of the vessel ar ranged vbehind this overflow device contains the acid, for example 30% sulphuric acid,

which is introduced through the supply pipe fshortly behind the overflow g for the salt" solution and is again withdrawn at the end of the precipitant container through the second overflow device 9.

The viscose solution is forced into the vessel through the nozzles a and coagulates on its passage through the salt solution present in the part A. The filament is led over the partition Within the body of said solutions and on its further passage through the second part of the vessel it is transformed into cellulose hydrate and the filament is fixed by the action of the acid. In this manner of producing artificial filaments the cellulose filament is Withdrawn at the end of the bath possessing greater strength so that it can be led off withoutdifiiculty on suitable wind-- In order to prevent;

ing devices or the like. any dangerous after elfect of the strong acid, the artificial threads are preferably caused, shortly after leaving the acid bath to be washed with Warm Water or steam. If desired, instead of inorganic salts, suitable organic coagulating media can also be substituted in the first part A of the bath in order to produce the precipitation of the viscose.

Similarly, the method of operation above described can also be utilized in the production of films and like formations from viscose solution.

The improved process is particularly suitsignature.

ARNOLD BERNSTEIN.

able for the production of very fine silk filak ments'as in this manner of forming the cellulose filament a very uniform and fine drawing out is rendered possible.

WVhat I claim is 1. In apparatus for forming artificial'tissues from viscose solution the combination of a vessel adapted to contain liquid, a partition of less height than said vessel dividing said vessel into two separate compartments,

ment'located adjacent and above the upper edge of said partit on, means to introduce an acid solution into said other compartment adjacent said partition, means to'remove said acid solution from the opposite end of said second compartment and located above the upper edge of said partition, means to introduce viscose solution into the outer end of said first compartment and means to draw the coagulated viscose body through said first and second compartments.

2. Apparatusfor forming artificial filaments and the like from viscose solution comprising a single container, a partition Within said container extending from the bottom thereof to a height less than the height of the Walls of said container to divide said container into tWosubst-antially separate compartments adapted to form a precipitating bath and afixing bath, means to introduce pricipitant solution into said first compart ment, means to remove said precipitant solution from said first compartment located 

